diff --git a/tests/unit/security/transform/digest-filter.t.cpp b/tests/unit/security/transform/digest-filter.t.cpp
index fced1b8..08f85cf 100644
--- a/tests/unit/security/transform/digest-filter.t.cpp
+++ b/tests/unit/security/transform/digest-filter.t.cpp
@@ -22,13 +22,14 @@
 #include "ndn-cxx/security/transform/digest-filter.hpp"
 
 #include "ndn-cxx/encoding/buffer-stream.hpp"
-#include "ndn-cxx/security/impl/openssl.hpp"
 #include "ndn-cxx/security/transform/buffer-source.hpp"
 #include "ndn-cxx/security/transform/step-source.hpp"
 #include "ndn-cxx/security/transform/stream-sink.hpp"
 
 #include "tests/boost-test.hpp"
 
+#include <openssl/evp.h>
+
 namespace ndn {
 namespace security {
 namespace transform {